Dystonic neck muscles show a shift in relative autospectral power during isometric contractions

Journal article (2017)

Authors

E. de Bruijn Biomechatronics & Human-Machine Control - Mechanical, Maritime and Materials Engineering
S.W.R. Nijmeijer Amsterdam UMC
P.A. Forbes Biomechatronics & Human-Machine Control - Mechanical, Maritime and Materials Engineering
J.H.T.M. Koelman Amsterdam UMC
F.C.T. van der Helm Biomechatronics & Human-Machine Control - Mechanical, Maritime and Materials Engineering
M.A.J. Tijssen Rijksuniversiteit Groningen
R. Happee Intelligent Vehicles - Mechanical, Maritime and Materials Engineering
Research Group
Intelligent Vehicles (Mechanical, Maritime and Materials Engineering) (TU Delft)
Copyright: © 2017 E. de Bruijn, SWR Nijmeijer, P.A. Forbes, JHTM Koelman, F.C.T. van der Helm, MAJ Tijssen, R. Happee
DOI
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https://doi.org/10.1016/j.clinph.2017.06.258
Cervical dystonia EMG Autospectrum Isometric contraction Cumulative distribution function
More Info
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Published Date

2017

Language

English

Faculty

Mechanical, Maritime and Materials Engineering

Department

Cognitive Robotics

Research Group

Intelligent Vehicles

Abstract

Objective
To identify effects of a deviant motor drive in the autospectral power of dystonic muscles during voluntary contraction in cervical dystonia patients.
Methods
Submaximal (20%) isometric head-neck tasks were performed with the head fixed, measuring surface EMG of the sternocleidomastoid, splenius capitis and semispinalis capitis in CD patients and controls. Autospectral power of muscle activity, and head forces was analyzed using cumulative distribution functions (CDF). A downward shift between the theta/low alpha-band (3-10 Hz) and the high alpha/beta-band (10-30 Hz) was detected using the CDF10, defined as the cumulative power from 3-10 Hz relative to power from 3-30 Hz.
Results
CDF10 was increased in dystonic muscles compared to controls and patient muscles unaffected by dystonia, due to a 3-10 Hz power increase and a 10-30 Hz decrease. CDF10 also increased in patient head forces.
Conclusions
Submaximal isometric contractions with the head fixed provided a well-defined test condition minimizing effects of reflexive feedback and tremor. We associate shifts in autospectral power with prokinetic sensorimotor control.
Significance
Analysis of autospectral power in isometric tasks with the head fixed is a promising approach in research and diagnostics of cervical dystonia.